Propeller.



No. 676,900. Patented June 25, I901. B. LEHMAN.

PROPELLEB.

(Application filed Feb. 18, 1901,)

IN VE N701? Mm.

UNITED STATES PATENT rmcn.

ISADOR LEHMAN, OF CLEVELAND, OHIO.

PROPELLER.

SPECIFICATION forming part of Letters Patent No. 676,900, dated June 25,1901.

Application filed February 18, 1901. Serial No. 47,842. (No model.)

To all whom it may concern:

Be it known that I, ISADOR LEHMAN, a resident of Cleveland, in thecounty of Guyahoga and State of Ohio, have in vented certain new anduseful Improvements in Propellers; andI do hereby declare the followingto be a full,elear and exact description of the invention, such as willenable others skilled in the art to which it pertains to make and usethe same.

My invention relates to improvements in propellers.

The object of this invention is to construct a propeller that hasgreater efliciency than the propellers heretofore devised; and with thisobject in View and to attain certain other advantages hereinafterappearing the invention consists in certain features of construction andcombinations of parts hereinafter described, and pointed out in theclaims.

In the accompanying drawings, Figure I is a side elevation of apropeller embodying my invention. Fig. 11 is a top plan relative toFig. 1. Figs. III and IV are opposite end elevations, respectively, ofthe propeller. Fig. V is a plan of the propeller looking downwardly uponthe outer end of one of the small blades e of the propeller and isapproximately a left-hand side elevation relative to Fig. III.

Referring to the drawings, a designates the propeller-shaft.

My improved propeller comprises a set of propelling-blades 1),preferably three in number. The three blades 1) are arranged,preferably, at equal intervals circumferentially of the shaft a. Eachblade I) projects laterally of the shaft and extends longitudinally ofthe shaft a suitable distance. Each blade Z7 is arranged at an angle tothe shaft. The blades 1) correspond, preferably, in their arrangementrelative to the shaft and are constructed and applied, preferably, asfollows: Two spiders c and d are mounted upon the shaft Ob andoperatively connected with the shaft, preferably by the well-known meansof groove and feather, as at. f, and are preferably rigidly secured tothe shaft by means of set-screws g. Each of the said spiders has acentral hub 7, embracing the shaft or and provided with as many radiallyor approximately radially arranged arms as there are blades 1),

and 8 and 9 designate the arms of the spiders c and d, respectively. Thetwo spiders c and d are set in such different positionscircumferentially of the shaft a that the arms 8 of the spider c and thearms 9 of the spider cl shall alternate in end elevation of thepropeller, and the arms of the two spiders of the propeller illustratedform three pairs of arms, with each arm of each spider forming one ofthe arms of a pair of arms. The arms of each pair of arms belong,therefore, to the different spiders c and cl, respectively, and

' diverge in end elevation of the propeller and participate in theformation of a blade I), as

will hereinafter more fully appear. Each arm of each spider is arrangedat an angle in end elevation of the said arm to the hub of the saidspider, and consequently at a corresponding angle to the shaft a. Thespiderarms preferably correspond in their angular arran gement. relativeto the shaft. The arms of each of the aforesaid pairs of spider-arms areenlarged in width toward each other, as at 10, between their outerextremities and a point about midway between their opposite ends, and asuitably-curved plate h of preferably uniform or approximately uniformthickness throughout is secured to the outer and Wider portions of thesaid arms, prefer ably removably, by means of screws 70, which plate 7textends, preferably, from endto end of the said Wider and outer portionsof the said arms, but does not extend inwardly beyond the said widerportions of the said arms, so as to form a water-passage-Way-formingopening 12, extending laterally through and centrally of the innerportion of the blade b, which is formed by the said plate. h and thespider-arms supporting or carrying the said plate It. The opening 12 inthe inner portion of each blade b not only materially ligl1tens theblade, but facilitates the operation of the blade.

The old'construction of propeller-blade involving a solid blade requiredadditional thickness in the blade next to the hub of the propeller-wheelto render the blade strong enough, and the work of propelling was doneby the outer and wider portion of the blade, and the inner and thickerand solid portion of the blade impeded the operation of the blade. Theseobjectionable features are IOO avoided in my improved construction,which not only forms a blade which is exceedingly strong and durable andcomparatively cheap, but which renders practical the use, in forming theouter portion of the blade, of a plate h of uniform thickness andcomparatively light.

The spider-arms have their outer and wider portions gradually reduced inthickness toward their inner side edges, so as to avoid square or abruptshoulders at the said edges, and I would here remark that the plate h ofeach blade 1) preferably overlaps the pair of spider-arms participatingin the formation of the said blade at one and the same side of the saidpair of arms.

I would remark that my improved construction, hereinbefore described,without any additional features constitutes a superior and advantageousand efficient form of propeller; but to still further enhance theefficiency of the propeller another set of propelling-blades e,alternating with the blades b, is preferably provided. The set of bladese comprises, therefore, three blades, arranged each preferably centrallybetween two adjacent blades 1). The blades e are formed upon a hub 14,which embraces the shaft or, and is operatively connected with the saidshaft a by the groove and featherf, and rigidly secured to the shaft toprevent endwise displacement thereof by suitably applied set-screws Z.Each blade '8 projects laterally of the shaft between the two adjacentblades b and is arranged at an angle to the hub 14 and extends from theinner end of the arm 8 of one of the said blades 1) to the inner end ofthe arm 9 of the other of the said blades b,- and the said blade e isarranged, therefore, as re quired to operate upon the water passingthrough the opening 12 of the one or the other of the two adjacentblades 12, according as the propeller rotated in the one or the otherdirection. The blades e project, preferably, about one-half as far fromthe shaft as the blades b and are preferably just large enough to.effectually operate upon the water passing through and between the innerportions of the blades 1).

Of no inconsiderableimportance is the participa'tion of the arms of thespiders c and d in the formation of the blades 1). As already indicated,the two spider-arms 8 and 9, participating in the formation of eachblade I), are correspondingly arranged at an angle to or diagonally ofthe propeller-shaft and are flat in end elevation, so that the sides ofthe tions of the arms or members 8 and 9 of each blade I), andespecially the widthwise enlargement of the said arms toward each other,is important, in that the said enlargement reinforces the plate h of thesaid blade.

WVhat I claim is-- 1. A propeller comprising a shaft, a set ofpropelling-blades arranged at suitable intervals circumferentially ofthe shaft and formed by the following: two spiders operatively mountedupon and a suitable distance apart 7 to or diagonally of the axial lineof the propeller,and the aforesaid arms having fiat sidescorrespondingly angularly arranged to the said axial line and formingefficient working surfaces.

2. A propeller comprising a shaft, a set of propelling-blades arrangedat suitable intervals circumferentially of the shaft and formed by thefollowing: two spiders operatively mounted upon and a suitable distanceapart longitudinally of the shaft and having pairs of radially orapproximately radially arranged flat arms arranged at an angle, in endeleva tion, to the shaft, with the two arms of each pair of arms beingmembers of the different spiders, respectively, and diverging towardtheir outer ends in end elevation of the pro= peller, and with one ofthe said arms having its outer portion enlarged in width, and a platesecured to the outer portion of the arms of each pair of arms andextending inwardly from the outer ends of the said pair of arms asuitable distance.

3. A propeller comprising a shaft, a set of propelling-blades arrangedat suitable intervals circumferentially of the shaft and formed of thefollowing: two spiders operatively mounted upon and longitudinally ofthe shaft and having pairs of radial or approximately radial armsarranged, in end elevation, at an angle to or diagonally of the shaft,with the two arms of each pair of arms being members of the differentspiders, respectively, and diverging toward their outer ends in endelevation of the propeller, and having their outer portions enlarged inwidth toward each other, and a plate secured to the outer and widerportion of the arms of each pair of arms and extending inwardly from theouter ends of the said arms a suitable distance.

4. A propeller comprising a shaft, a set of propelling-blades arrangedat suitable inter-' vals circumferentially of the shaft and formed bythe following: two spiders operatively mounted upon and a suitabledistance apart longitudinally of the shaft and having pairs of radiallyor approximately radially arranged arms arranged at an angle in endelevation to the shaft with the two arms of each pair of arms beingmembers of the different spiders, respectively, and diverging towardtheir outer ends in end elevation of the pro peller and having theirouter portions enlarged in width and gradually reduced in thicknesstoward their inner side edges, and a plate secured to the outer andwider portions of the arms of each pair of arms and extending inwardlyfrom the outer ends of the said arms a suitable distance, substantiallyas and for the purpose set forth.

5. A propeller comprising a set of suitablyarranged propelling-bladeshaving water-passage-way-forming openings extending laterally throughthe inner portions of the blades, and another set of propelling-bladesalternating with the first-mentioned blades and arranged to operate uponthe Water passing through the openings of and between the firstmentionedblades, substantially as and for the purpose set forth.

6. A propeller comprising a set of suitablyarranged propelling bladesprovided with openings extending laterally through the in ner portionsof the blades, and another set of smaller propelling-blades alternatingwith the first-mentioned blades and arranged centrally between the innerand open portions of the said first-mentioned blades, substantially asand for the purpose set forth.

7. A propeller comprising a shaft, two hubs 7 and 7 operatively mountedupon the shaft a suitable distance apart longitudinally of the shaft andprovided with suitably-arranged propelling-blades provided with openingsextending laterally through the inner portions of the blades between theaforesaid hubs, and another hub operatively mounted upon the shaftbetween the two first-mentioned hubs and having propelling-bladesalternating with the first-mentioned blades and arranged to operate uponthe water passing through the openings of the said first-mentionedblades.

Signed by me at Cleveland, Ohio, this 14th day of February, 1901.

ISADOR LEI-IMAN WVitnessesi O. H. Donne, A. H. PARRATT.

